The CITE Graph service

NB: this is a preliminary description of the CITE Graph service, and is not in final form.

Request and reply

Like the CTS and CITE Collection services, CITE Graph is a RESTful service accepting requests via HTTP parameters and returning replies formatted in XML.

The current version of graph accepts a single parameter, urn.

The reply is formatted as in the following example:

<citegraph xmlns='http://www.homermultitext.org/xmlns/hmtgraph'>
<request><urn>urn:cite:hmt:msA.msA-12r</urn>
<tripletServer>http://localhost:3030/ds/</tripletServer>
 </request>
<reply>
<arcNamespace uri=""http://www.homermultitext.org/hmt/rdfverbs/"/>
<graph urn='urn:cite:hmt:msA.msA-12r'>
<node arc='next' urn='urn:cite:hmt:msA.msA-12v'/>
<node arc='illustratedBy' urn='urn:cite:hmt:chsimg.VA012RUVD-0895'/>
<sequence arc='hasOnIt' urn='urn:cts:greekLit:tlg0012.tlg001.msA:1.1-1.25'>
<node arc='hasOnIt' urn='urn:cts:greekLit:tlg0012.tlg001.msA:1.1'/>
<node arc='hasOnIt' urn='urn:cts:greekLit:tlg0012.tlg001.msA:1.2'/>
<node arc='hasOnIt' urn='urn:cts:greekLit:tlg0012.tlg001.msA:1.3'/>
</sequence>
</graph>
</reply>
</citegraph>       

The root hmtgraph element contains a single request element followed by a single reply element.

The reply element contains a single graph element with a urn attribute identifying the requested object. It contains one or more instances of node or sequence elements. node elements are always empty, and must have an arc and urn attribute.

The sequence element has a urn attribute with a range expression, and contains one or more node elements.

In the example above, values for the @arc attribute are taken from the Homer Multitext project RDF vocabulary. See more information about the verbs used in the node’s @arc attribute.